An umpolung strategy for rapid access to thermally activated delayed fluorescence (TADF) materials based on phenazine
作者:Huaxing Zhang、Qiang Guo、Hu Cheng、Chunhao Ran、Di Wu、Jingbo Lan
DOI:10.1039/d1cc06705b
日期:——
radical nucleophilic addition/rearrangement of 2-aryl diazaboroles has been accomplished for the first time to construct phenazine structures. This protocol is an umpolung strategy based on the classical electrophilic mechanism, and therefore, a reversed regioselectivity was observed, which provides an opportunity to prepare sterically hindered phenazines. The resulting thermally activated delayed fluorescence
Metal ions and complexes in organic reactions. Part XVIII. Structural variations in the production of polycyclic heterocyclic systems by iron(II)-promoted cyclisations of nitro-substituted precursors
作者:Reginald G. R. Bacon、S. Dennis Hamilton
DOI:10.1039/p19740001970
日期:——
cyclisation, through the nitro-group, gave compounds (5–20%) in the following polycyclic series: thieno[2,3-b]quinoxaline (3), imidazo[1,2-a]quinoxaline (7), benzimidazo[1,2-a]quinoxaline (9), and benzo[g]pteridine (11); a 2-methyl substituent on an imidazole nucleus contributed to the central pyrazine ring in structures (7) and (9). o-Nitrodiphenylmethane gave o-aminobenzophenone and acridone. Nitro(pyridylamino)pyridines
描述了涉及结构X–Y或X–NH–Y中具有与核间键邻位的硝基取代基的中间体的合成方法,其中X =苯基,Y =噻吩基,吡唑基,咪唑基或嘧啶基。将这些化合物与草酸亚铁(II)加热至约200℃。280°主要给出相应的伯胺(最高约65%),有时还提供相应的偶氮化合物。通过硝基进行竞争性环化,得到以下多环系列化合物(5-20%):噻吩并[2,3- b ]喹喔啉(3),咪唑并[1,2- a ]喹喔啉(7),苯并咪唑[1,2- a ]喹喔啉(9)和苯并[ g蝶啶(11); 咪唑核上的2-甲基取代基有助于结构(7)和(9)的中央吡嗪环。邻硝基二苯甲烷得到邻氨基二苯甲酮和a啶酮。合成了硝基(吡啶基氨基)吡啶作为二吡啶并吡嗪的潜在来源,但它们容易裂变为相应的氨基硝基吡啶。
AMES, D. E.;MITCHELL, J. C.;TAKUNDWA, CH. C., J. CHEM. RES. SYNOP., 1985, N 5, 144-145